Warren states that there is no limitation to abortion and it is always justifiable. A fetus or infant are not considered persons. To Warren it is wrong to kill an innocent human being but a fetus is not a human being, so therefore, it is not wrong to kill a fetus. A fetus or infant has not reached personhood due to the five traits which Warren describes makes a person. The traits that make a person, according to Warren are: consciousness, reasoning, self-motivated activity, ability to communicate, and self-awareness. The first two in Warren's list are necessary for personhood, the third is sufficient for personhood. The last two are part of the traits that make up personhood. Since fetus' do not fall under these traits, according to Warren, abortion is not immoral.
Don Marquis argues that abortion is immoral. The killing of an individual that has a valuable future is immoral. Marquis believe is murder if the depravation of an individual's valuable future, fetuses have a valuable future; therefore it is abortion is murder. A valuable future is one that an individual can have experiences, activities, projects, and enjoyments. The killing is wrong because it takes away the victims life and everything that individual could experience or do in life. If a person is severely ill or incurable and wish to die have not suffered a loss of life, it is the person's future that what makes this argument morally correct or incorrect. Depriving an individual of a valuable future is immoral whether it be a fetus, an infant, or an adult it is immoral to Marquis.